Arch-vile jump

From DoomWiki.org

The arch-vile jump is a speedrunning technique that permits the player to jump very high by allowing himself to be hit by the arch-vile's fire attack. When the arch-vile detonates his column of fire, the player is flung up into the air. If the player is moving forward at the moment the column detonates he can use the height imparted to him to make a super jump over walls, large gaps, and through windows that are otherwise unreachable. As the technique is something of an exploit, it was very likely not meant to exist and will often allow the player to access parts of levels that were not meant to be accessed, or it may act as a sequence break and allow the player to skip collecting a key or hitting an otherwise required switch.